A variety of applications require the provision of an optic energy flux between cooperating optic elements, e.g., between two optic fibers or from a relatively expensive long-use optic element such as an optic fiber into a disposable end-use element which may become damaged or contaminated during use. One example of the latter type of use is a laser surgical system in which the surgeon holds a slim elongate tool connected via an optic fiber to a laser energy source. The surgical tool is usually formed to utilize a controlled flux of laser energy at a surgical tip element.
As the surgeon employs the tip element, either to radiate laser energy to vaporize tissue and thereby perform incisions, or to apply a heated portion of the tip element to cauterize tissue or to coagulate body fluids, the material of the tip element is subjected to severe thermal cycling. In addition, due to carbonization of heated body tissue on its surface, the efficiency of the surgical tip may be reduced over time. When damage to or deterioration of the tip element becomes unacceptable, or as different types of tissue are encountered during surgery, the surgeon may want to replace the tip element.
If the tip element were integrated with the optic fiber connected to the laser energy source its replacement would be very expensive and could be time-consuming and tedious. It is therefore desirable to provide a disposable laser energy delivering tip element assembly which can be quickly and efficiently coupled optically to a long-use optic fiber end that is protected within the hand-held surgical tool. Such a facility would also allow a surgeon to simply replace one tip element/assembly with another, e.g., to operate on a different patient, quickly and easily. Similarly, the surgeon may selectively use a succession of differently shaped and sized tip elements as he or she encounters different types of tissues and needs in operating on a single patient.
A variety of laser surgical systems including disposable elements are known. These include, for example, those patented in U.S. Pat. Nos. 4,785,805 and 4,895,145, both to Joffe et al. These patents provide a two-component laser delivery system for surgical and endoscopic applications. The disclosed apparatus includes a reuseable head portion for insertion into a laser energy generating apparatus and a disposable optic guide portion engageable therewith. However, making the integrated system from the laser source onward disposable may be quite expensive and is preferably avoided. The problem, therefore, narrows down to how to efficiently couple the distal end of an optic fiber via a disposable and relatively inexpensive optical interface and thus to a tip element in such a way that transmission losses are minimized and tip elements readily replaced by a busy surgeon.
Although the preferred embodiment described below with reference to the accompanying drawing figures relates to a laser surgical application, it should be appreciated that the invention may be readily utilized in other applications. For example, an inspection system in a radioactive environment may include an optical fiber through which a flux of optical energy is sent in a forward direction and through which a portion of reflected optic energy is returned for analysis. Such a system may include a disposable end element exposed to radioactivity and therefore needing to be replaced periodically. Another example may be the use of optic observation and sensing elements disposed on space craft where there may be eventually eroded or otherwise damaged and may have to be replaced in space by astronauts operating under severe physical constraints. It is believed that the invention described below solves these and other comparable problems requiring efficient optical coupling between any two cooperating optic elements, and may be advantageously used to optically couple a long-use optic element and a cooperating replaceable element.